From 45604de32833ccb0b627b542d7b68b9ef8f37c73 Mon Sep 17 00:00:00 2001
From: Poul-Henning Kamp <phk@FreeBSD.org>
Date: Sat, 2 Oct 1999 11:17:54 +0000
Subject: [PATCH] Fix a problem relating to si_iosize_max which broke scsi
 devices.

---
 sys/kern/kern_physio.c |  4 ++++
 sys/kern/subr_disk.c   | 12 +++++++-----
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/sys/kern/kern_physio.c b/sys/kern/kern_physio.c
index 01bc7f3593c..6bf3e7f4b82 100644
--- a/sys/kern/kern_physio.c
+++ b/sys/kern/kern_physio.c
@@ -175,6 +175,10 @@ minphys(bp)
 	u_int maxphys;
 
 	maxphys = bp->b_dev->si_iosize_max;
+	if(!maxphys) {
+		printf("WARNING: %s maxphys = 0 ??", devtoname(bp->b_dev));
+		maxphys = DFLTPHYS;
+	}
 	if (bp->b_kvasize && (bp->b_kvasize < maxphys))
 		maxphys = bp->b_kvasize;
 
diff --git a/sys/kern/subr_disk.c b/sys/kern/subr_disk.c
index bfa3d894257..9c53bdeaa53 100644
--- a/sys/kern/subr_disk.c
+++ b/sys/kern/subr_disk.c
@@ -115,8 +115,10 @@ diskopen(dev_t dev, int oflags, int devtype, struct proc *p)
 	if (!dp)
 		return (ENXIO);
 
-	if (!dsisopen(dp->d_slice))
+	if (!dsisopen(dp->d_slice)) {
+		pdev->si_iosize_max = dev->si_iosize_max;
 		error = dp->d_devsw->d_open(pdev, oflags, devtype, p);
+	}
 
 	/* Inherit properties from the whole/raw dev_t */
 	dev->si_disk = pdev->si_disk;
@@ -163,12 +165,12 @@ diskstrategy(struct buf *bp)
 	dp = bp->b_dev->si_disk;
 	if (!dp) {
 		pdev = dkmodpart(dkmodslice(bp->b_dev, WHOLE_DISK_SLICE), RAW_PART);
-		dp = pdev->si_disk;
+		dp = bp->b_dev->si_disk = pdev->si_disk;
 		bp->b_dev->si_drv1 = pdev->si_drv1;
 		bp->b_dev->si_drv2 = pdev->si_drv2;
-		/* XXX: don't set bp->b_dev->si_disk (?) */
-	} else {
-		pdev = dp->d_dev;
+		bp->b_dev->si_iosize_max = pdev->si_iosize_max;
+		bp->b_dev->si_bsize_phys = pdev->si_bsize_phys;
+		bp->b_dev->si_bsize_best = pdev->si_bsize_best;
 	}
 
 	if (!dp) {